I don't think it was the wrong time, it was just Koh Phi Phi. I don't know why people still go to Koh Phi Phi really. It is widely known as being one of the most popular destinations in Thailand for global tourists, which for Thailand almost unanimously means it will NOT be pleasant in 2023. The tourists that go to these places do not have high standards. With other countries people want to avoid other tourists, so why do people act the opposite with Thailand?
There are several islands and locations in the same region that are immensely more pleasant and comparably undertouristed. But people seem magnetically attached to Phi Phi despite knowing the bad reviews and it being overdeveloped/crowded. Same as when people go to Phuket and end up in Patong and it's like yeah, what you expect haha?
Not trying to slate you or anything but I see it a ton with complaints of popular tourist destinations. If you want a special experience, you gotta read around a little more and find the islands that Thai's would actually visit (think Koh Yao Noi, or the , that are less developed but will still cater to high end tourism. Anything else and you are just going with the crowds and you will get a poor experience to match.